<!DOCTYPE html>
<html lang="en">

<head>
    <meta charset="UTF-8">
    <meta http-equiv="X-UA-Compatible" content="IE=edge">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>proxy</title>
</head>

<body>
    <script>
        let obj = {
            name: "张三",
            age: 20
        };

        let newObj = new Proxy(obj, {
            get(target, key) {
                console.log('get');
                return Reflect.get(target, key)
            },
            set(target, key, newValue) {
                console.log('set');
                return Reflect.set(target, key, newValue);
            },
            has(target, key) {
                console.log(target, key);
                if (target[key]) {
                    return true;
                }
                return false;
            }
        });

        newObj.name;
        newObj.name = '李四';
        console.log('name' in newObj);
    </script>
</body>

</html>